Thursday, June 25, 2009

Re: Max. temperature for concrete

        As it happens, you were one of the named persons in my posting of 11/3/2005.  I usually delete these responses after 3 or 4 weeks; but, for some reason, I decided to save that one for future use; and today an opportunity arose.
        As I recall (and the older I get the more warn out my recaller becomes) sulphur melts at about 243 degrees F, so it's not the temperature that causes the deterioration in tanks within my experience; it's the difference in temperature between the inside and outside faces of the walls and floor which causes substantial bending stresses beyond the cracking stress.  but, more importantly, the most destructive element is the corrosive attack of the mixture of sulphur vapor, oxygen (from the air) and water vapor that is present in the space above the liquid surface.  I've seen sulphur tanks where the concrete below the liquid level still had formwork marks even after several years of use, yet above the liquid surface the concrete was corroded away beyond the reinforcing.
H. Daryl Richardson
----- Original Message -----
Sent: Thursday, June 25, 2009 12:01 PM
Subject: Re: Max. temperature for concrete

That would be my assessment, too. 
Although beyond, say, 2" of concrete the temperatures are lower, on the surface they are high enough to start irreversible and progressive thermal deterioration.
V. Steve Gordin, SE
Irvine CA
----- Original Message -----
Sent: Thursday, June 25, 2009 11:01
Subject: Re: Max. temperature for concrete

Bevin, Tom,
        When I see the terms liquid sulphur storage, reinforced concrete tank, and crack free design used in the same paragraph my first reaction is "Ha ha ha ha ...."  Please don't think I'm mocking you; I'm not.
        I responded to a request for information on storage tank design on this list on 11/3/2005, and followed up privately on 11/4/2005.  These responses were very lengthy so I will not repeat them here; but I will forward them to both of you privately.
        Reinforced concrete tanks used for liquid sulphur storage lack durability to the point where, in a very few years, they can become outright dangerous, never-the-less, they remain the most practical solution to the problem of storing liquid sulphur in the short term.  More to follow privately.
H. Daryl Richardson
----- Original Message -----
Sent: Thursday, June 25, 2009 9:46 AM
Subject: Max. temperature for concrete

Pl. let me know that what is the maximum temperature bare concrete can withstand, in case of liqquid sulphur storage pit (concrete strength = 4000 psi, crack free design).